Transmission



' 1,668,163 K. E. L YMAN f TRA'NSMIssIoNv Filed N ov. 24. .1926

May -l, 1928.

4 Sheets-Sheet 1 76 50 INVENTOR Byzn ATTORNEY KENNETH E.LYMAN May 1,1928. 1,668,163

K. E. LYMAN TRANSMISSION Filed Nov.24. 192e/ 4 4 sheets-sheet 2- INVENTOR ,-76,9 l KEN NEI-TH Lw/MAN 'N y ATTORNEY May 1, 1928. 1,668,163

K. E. LYMAN y TRANSMISSION Filed Nov. 24. 192e 4 sheets-sheet 5 INVENTOR F/qjg A Kl-:NrgYTH E. LYMAN ATTORNEY May 1, 1928.

K. E. LYMAN TRANSMISSION Filed Nov. 24. 1926 4 Sheets-Sheet 4 W-Av /76 'l y INVENTOR TH ELYMAN ATTORNEY rection, as for example in driving up 'to the Patented May l, 1928.

UNITED ySTATES PATENT OFFICE.

KENNETH E. LYMALN, OF CHICAGO, ILLINOIS, ASSIGNOBTO MOTOR INDUSTRIES, INC., OF CHICAGO, ILLINOIS,.A CORPORATION OF ILLINOIS.

TRANSMISSION.

Application led November 24, 1926. Serial No. 150,513.

This invention relates to transmissions and is illustrated as embodied in a changespeed'transmission Aot the sliding gear type for use in an automobile or other powerdriven vehicle. An object of the invention -is to provide simple and automatically-operated means for preventing 'the vehicle from moving-in the opposite direction to that desired by the driver,-that is, to prevent the vehicle from moving backward when the gearing is set for a forward motion, and to prevent the vehicle from moving forward when the gearing is set in reverse. One advantage of an arrangement of this sort is that it is unnecessary to hold the `vehicle on a grade with the brake when waiting for an opportunity to get through the cross traffic.

One important featureof the invention rclates to the provision of a device which acts by engagement with one or more of the teeth of one of the regular change-speed gears, preferably one of the gears on the counter shaft which turns in the same direction whether the change-speed gearing is set for forward motion or is set in reverse. This permits the use of the device on almost any standard transmission with practically no change in the transmission itself. It also permits a slight'movement of the vehicle in the undesired direction beiore the safety de vice engages the next tooth ot' the gear, this movement of a few inches in the wrong direction being preferred in order to guard against locking the transmission when there are very slight movements in the wrong dicurb in parking hard enough to compress the front tires slightly and force the car a few inches backward when its inertia has been overcome.

Another important feature of novelty. preferably but not necessarily embodied in the inventionat the same time that the feature of engagement with the geur teeth is used, is in causing the automatic movement of the safety device to and from a position in which it prevents'the rotation of the gear or other rotatable member in the wrong direction, by means of a drag against the rotatable member, as for example by means of a device yieldingly engaging the side or both sides of the gear or other rotatable member so that its drag on that member acts automatically to shift the safety device to and from its rotation-preventing position.

Other 'features of novelty relate to novel means for manually releasing the safety device when desired, and to particular constructions of 'the device for preventing rotation of the gear or other member, and to other novel combinations of parts and de sirable yparticular constructions which will be apparent from the lfollowing description of a number of desirable embodiments shown in the accompanying drawings, in which:

Figure l is a diagrammatic top plan view of an vautomobile chassis showing the' relation of the transmission to the other parts of the chassis;

Figure 2 is a longitudinal vertical section through the transmission, showing the change-speed gears;

Figure 3 is a section generally on the line 3*-3 of Figure 2 and showing the transmission in transverse vertical section, one form of safety device being shown partly in rear elevation and partly in central section;

Figure 4 is a partial section on the line 4 4 of Figure 3, showing the engagement with the sides of one of the gears of a pair of yielding members which drag against the gear in such a manner as to operate the safety device;

Figure 5 is a partial section on the line 5-5 of Figure 3, showing the safety device and part of one of the gears with which it is engagea-ble;

Figure 6 is a view corresponding to Fig ure 5 but showing a modified form of safety device;

Figure 7 is a view corresponding to part of Figure 5 and showing a third form ot safety device:v y

Figures 8-18 inclusive are respectively views corresponding to Figure 7 and each of which shows a different form of safety device;

Figure 19 is a view corresponding to that part of Figure `18 which shows the safety device. hut showing a modified mounting for the safety device;

Figure 20 is a section on the line 20-20 of Figure 19 and showing the modilied mounting in elevation;

eisk

Figures 21 and 22 are views corresponding respectively to Figures 19 and 20` but showing a third mounting for the safety device; and

Figures 23, 24, and 25 are views corresponding to Figure 7 but showing three additional modifications of the safety device.

The invention is illustrated .as embodied iii a change-speed transmission for an automobile chassis including a frame 32-carrying the engine 34 and supportedby a front axle 36 mounted on the i'oad wheels 38 and by a rear axle 40 mounted on the road wheels 42. "1`he road wheels 42 'may be driven from engine 34 through the usual clutch and through the transmission 30 operating the usual propeller shaft 44.

The illustrated transmission lis of the conventional sliding gear type and includes a driving shaft 46 operated by the clutch and terminating in afV ear 48 which is permanently in mesh wit i a gear 50 forming part of a rotatable gear unit mounted on a countershaft 52 carried by the transmission casing 54. The shaft 46 is formed at its rear end to serve as a bearing for the front end 56 of a splined driven shaft 58 which is rotatably mounted at its rear end in the transmission casing 54 and which is connected to the propeller shaft 44 through any suitable universal joint 58. The transmission brake 60 is also shown atthe rear end on the spliiied driven shaft 58 are a pair of gears 62 and (i4 operated by the usual shifte`V forks V(S6 which are operated by the universally mounted gear shift lever 68 and which are slidably supported on stationary shafts 70 mounted in the transmission casing 54. The gear 64 can be moved by its shifter fork forwardlyv into mesh with a gear 72 of the unit driven by the gear 50, to give low or first speed, or rearwardly into mesh with a reverse gear 74 (Figure 3) driven by a gear 76 which forms part of the unit driven by the gear 50, to drive the vehicle in reverse. The gear 62 can be moved rearwardly into mesh with a gear 78 of the unit driven by the gear 50 to give second speed', or for# wardly to bring internal teeth on its front face into mesh with the teeth of the gear 4S to give the usual direct drive at high speed.

' It lwill be lappreciated that the foregoing description is of 4one standard t pe of change-speed gearing ordinaril use as an automobile transmission and t at the par,-` ticular construction of the transmission lor change-speed gearing itself forms no part of the present invention, which is applicable to transmissions and change-speed gearing of all kinds.

In the arrangement shown in Figures 3, 4, and 5, the safety device which prevents movement of the vehicle inl the wrong direction is in the form of a part 80 which is movable automatically tov and -from a po` driver whether that movement is forwardK or backward.,-that is, the gear 50 should move clockwise in Figure 3 whether the veliicle is being driven through one of the forward gear positions or through the reverse gear 74. Accordingly, it is sufficient in this arrangement to provide means opeiated by counter-clockwise movement of gear 50 to shift the safety device 80 into engagement with the teeth of the gear and also operated by movement. of gear 50 in its normal or clockwise direction to shift the Safety device 80 to a position in which it is ineffective.

In this particular arrangement the device 80 is provided with an opening at its upper end having parallel sides to be movably arranged on a flattened portion of a stationarily' mounted in a hollowoss 84 integrally formed on the side of the'casing 54, and projecting inwardly of the casing. Means such as a cotter pin '86 prevents loss of the safety device 80 off vthe supporting post 82. The lit of the safety device 80. on the post 82 is quite loose so that the device may swing about its upper end as if pivoted.

When the device engages the teeth of the,

gear 50 to prevent its rotation in the undesired direction, the thrust from the gear-is taken through the device 80 and post 82 aiid v 54. In this thustransinitted to the casin particular arrangement the s ifting of the safety device 80 to and from its rotationpreventing position is accomplished by thedrag against the opposite' sidesof the gear 5() of a pair of spring arms 88 and 90 which preferably are integrally united by a connecting poi'tion 92 spot-welded or riveted 'or yotherwise'secured to the bottom of the safety device 80. As shown in Figure 6,

the device 80 may if preferred be mounted on a cylindrical post 94 instead of the Hatteiied part 82. I

In the particular arrangement shown in -F igure 3, the hollow boss 84 is arranged to serve as a fulci'iiiii or mounting for an operating lever 96 which in this. instance is` the hand brake lever which operates the emergency brake 60.

los

In the'operation of the vehicle it willbe seen that the spring arms 88 and'90 constantly drag against the opposite sides of `the gear 50V and. s o, long as the gear is .turn. ing'in its proper direction they swing the lower end of the device 80 awa from `the gear and ordinarily flat against t e side wall of the casing 54. If, however, the vehicle .iao v 'should start to drift backward when waitingy counter-clockwise direction) the drag of the arms 88 and 90 would swin the safety device away from the casing 54 until its lower end engaged one of the teeth of the gear 50, thus preventing any further rotation of the gear in the wrong-direction.

The arrangement shown 1n Figure 7 differs from that just described in that the safet device is in the form of an angular mem er 98 pivoted at its upper end on a bracket 100 and operated by spring arms 102 when the gear 50 turns in the wrong direction to ,brin ...its end 104 directly between the teeth o the gear 48 and the teeth of the gear 50. Vhile the end 104 wedges so firmly in place as to prevent further rotation of the gears, it is large enough in section to insure that it will not wedge itself between the teeth so that it cannot be released. y l

In Figure 9, the arrangement is generally the same as in Figure 3,.except that the safety device 106 is mounted on a pivot 108 carried by the bracket 110- on the casing 54, instead of merely having a loose iton the post 82 as in Figure 3. ,t

The modification of Figure 8 is somewhat similar to that of Figure 7, in that the safety device 112 is pivoted at its upper end and has a part 114 which prevents rotation in the wrong direction by being projected between the teeth of gears 48 and 50 by the drag ofthe spring arms 116 engaging the opposite sides of gear 50.

In Figure 10, the safety device is a plunger 118 slidably mounted on a fitting 120 carried by the casing 54 and shiftedeiidwise by spring arms 122 engaging opposite sides of gear 50 to move its left-hand end to and from a rotation-preventing position in which it projects between the teeth of the gears 48 and 50. The arrangement of Figure 11 is generally similar' to that of Figure 10 in that it includes a lplunger 124 shdably mounted for endwise movement in a fitting 126E carried by the casing 54, but in this ilistance the spring arms 128 are shown formed integrally with the plunger 124 and the part which is projected between the teeth of the gears 48 and 50 to prevent rotation 1n one directionv is a relatively large roller 13.0 carried by the plunger 124. -The gear 50 is shown with annular shouldered portions 132 serving to support the ends of the spring arms 128.4 In Figure 12, a pivoted safety 'device' 134 is used to carry the rollers 130 and spring arms 128.

before, but in this instance the plunger extends entirely through its fitting 138 to the outside of the transmissionvcasmg 54. At its outer .end the plunger 136 is slotted at 140 to receive a pin on the end of a bell- Acrank lever 142 which can be operated against the resistance of a return sprin 1 44 by a plunger 146 extending up throng the tloor boald into the drivers compartment of the car. This permits the depression of the plunger 146 to withdraw the safety device and permit the rotation of the gears in the wrong direction when the driver for any reason desires it.

In the arrangement of Figures 14 and 15, the safety device is a leaf spring 148 secured tothe casing at 150 and having a sharp part or tooth 152 which is moved by the drag'of a part 154 engaging lthe ends of the teeth of the gear 50.

In Figure 16 the safety device isa bellcrank lever 156 having one end turned at right angles and-inserted in a cam slot 158 and having the other end'160 also turned at right angles so tliat'it can be swung downwardly and to the left into a rotationpreventing position between the teeth of the gears 48 and 50. The lever 156 is pivoted between its ends on an arm 162 projecting from a disk 164 held in light rictional engagement with one face of the gear 50. So long as the gear 50 is turning in a clockwise direction, the disk 164 is turned as far as possible to swing the lower end' of the lever 156 to the bottom of the slot 158, thus withdrawing the end from between the teeth of gearsl 48 and 50. If, however. the gear 50 should turn in a counter-clockwise direction, thedisk 164 would also turn and would carry the lower end of the bellcrank lever 156 to the upper end of the slot 158,- which would swing the level' to pro ject-the end 160 between the teeth of the gears 48 and 50.

In the arrangement of Figure `17, the safety device is in the form of a long and generally vertical lever 168 carrying the spring arms 170 at its lower end and having this lower end arranged to engage one of .the teeth of4 thegear 50 to prevent its rotation in thewrong direction. The member 168 is mounted by a ball-and-socket joint 172-011 t-lie top ot' the casing 54 and, has its upper end 174 projecting through an opening in the floor hoard 176 into the drivers compartment of the car. It will be seen that the driver can put his heel on the upper end 174 and force it downwardlyl to withdraw the lower end of the device 168 from the teeth of the gear 50, thus permitting the gear'50 to rotate in the wrong direction when the driver desires it to do so.

In the arrangement of Figure 18, the safety device is a U-sliaped stamping 178 having the integral sides 180 serving as thel ius spring arms dragging against the sides of gear 50 and having its lower edge 182 serving as the part which is swung into engagement with one ot' the teeth of gear 50 to prevent .its rotation in the wrong direction. This safety device 178 is formed with a relatively large opening loosely fitting over the end of the stud 184 and retained thereon by means such as a cotter pin 86. In Figure 19, this safety device is mounted on a nut 188 held by a bolt 190 passing through the casing 54. In the arrangen'ient of Figures 2l and 22, the device is held by an ordinary round nut 192 on the bolt 190.

The arrangement of Figure 23 is substantially like that of Figure 18, except that the safety device 178 is mounted on a pivot 191 'arried b v the stud 184. The form in Figure 25 issubstantially like that ot' Figure 19 except that the inclination of the sides 196 is the opposite of the inclination of the sides 180.

In the arrangement of Figure 24, the

' spring arms 198 rest on the annular. shoulders 132 and are pivotcd at their ends to an eccentric 200 mounted on'a bracket 202 and provided with one idler tooth 204. When the gear 50 starts to turn the wrong direction the spring arms 198 turn the eccentric 200 lirst bringing the tooth 204 into mesh, whereupon further rotation of the gear 150 brings the eccentric'itself into the space between. the next two teeth, thuspreventing further rotation of the gear. The eccentric 200 may be regarded as a blank gear or segment of a gear in which only one tooth has been fully formed.

While various modifications of the invention have been described in considerable de tail, it is not my intention to limit its scope to those particular embodimentsor otherwise than by the terms of the appended claims.

I claim:

1. Transmission 4mechanism for a vehicle to be driven by an engine and including a gear rotating in the same direction whichever direction the vehicle is moving when driven by the engine, and comprising, in combination therewith, a device arranged to engage a tooth of said gear to prevent its rotation in the opposite direction.

2. Transmission mechanism for a vehicle including a gear, and comprising, in` combination therewith. a device arranged to engage a tooth of said gear to prevent its rotation in one direction, and means operated by engagement with the gear for rendering said device inoperative so long as the gear is turning in the opposite direction.

8. A vehicle transmission including change-speed gears, at least one of which normally rotates in the same direction in either direction of vehicle movement, and comprising, in combination therewith, a device engageable with a tooth of said one gear and automatically preventing its rota-I tion in the opposite direction.

4. A vehicle transmission including change-speed gears, and comprising, in combination therewith, a device engageable with a tooth of one of said gears and automatically preventing its rotation in one direction.

5. A vehicle transmission including change-speed gears, and comprising. in combination therewith, a device engageable with a tooth of one ot' .nid gears and automatially preventing its rotation in one direction, and means for rendering said device inoperative so long as the gear is turning in the opposite direction. k

6. A vehicle tansmission including change-speed gears, and comprising, in combination therewith, a device engageable with a tooth of one of said gears and automatically preventing its rotation in one direction, and means operated by engagement'with the gear for rendering said device inoperative so long as the gear is turning in the opposite direction.

7. A vehicle transmission including change-speed gears, and comprising, in combination therewith, a device engageable with a tooth of one of said gears and automati` cally preventing its rotation in one direction, and a resilient part dragging against the gear and arranged to 4hold the device out of engagement with the gear so long as the gear is turning in the opposite direction.

8.f A vehicle transmission including change-speed gears, and comprising, in combination therewith, a device engageable with a toothof one of said gears and automatically preventing its rotation in one direction, and a resilient part secured to said device and dragging against the gear and arranged to hold the device out of engagement with the gear so long as the gear is turning in the opposite direction.

9. A vehicle transmission including change-speed gears, and comprising, in combination therewith, a device engageable with a tooth of one of said gears vand automatically preventing its rotation in one direction, and a resilient part secured to said device and dragging against the gear and arranged to hold the device out of engagement with the gear so long 'as thevgear is turning in the opposite direction and to move the device into engagement with the gear when the gear reverses itself.

10. A vehicle transmission including change-speed gears, and comprising, in combination therewith, a device engageable with a tooth of one of said gears and automatically preventing its rotation in one direction, and a pair ot spring members carried 4by said device and engaging opposite faces of the gear and operated by the drag of the gear to move said device into and out= Aof engagement with the gear teeth according to the direction of rotation of the gear..

11. A transmission comprising, in combination, a Gear, a device engageable with the teeth of the gear, andmeans for automati- `.cally moving the device into and out of enga ement with the gear teeth to prevent rotation of the gear in one direction. 4

12. A transmission comprising, in combination, a ear, a device cngageable with the teeth of tie gear, and means' operated by a. drag on the gear for automatically moving the device into and out of engagement with the gear teeth to prevent rotationl of the gear in one direction.

13. A vehicle transmission comprising, in combination, a rotatable memberturning in the same direction in either direction of vehicle movement, and a device engageable with -said member to prevent its rotation in the opposite direction and including a part dragging against said member and Aoperated by the drag thereof to hold the device in an ineieetive position as long as the memberv turns in said same direction.

14. A vehicle transmission comprising, in combination, a rotatable member, and ka device engageable with said member to prevent its rotation in one direction and including ay part dragging against said member and oper'- ated by the drag thereof to'hold the device in an ineffective position as long as the member turns in the other direction.

15. A transmission comprising, in combination, avrotatable member, a device movable to and from a position in which it prevents rotation ofsaid member, and a part carried by said device and constantly engaging and dragging against said member and operated by the dragging to shift said device to and from rotation-preventing position when said member rotates in opposite directions.

16. A transmission comprising, in combi-- nation, a rotatable membeiga device movable to and from a position in which it 'prevents rotation of said member, and spaced yielding parts carried by said device and constantly engaging and dragging against the opposite sides" of said member and operated by the dragging-to shift said device to and from rotation-preventing position when said member rotates in opposite directions.

17. A transmission comprising, in combi-` nation, a casing, change-s eed means arranged withinthe casing an including a rotatable member, a stationary post secured in the.wal1 of said casing and rojecting in-v wardly therefrom, and a device within the casing which is movable into Iengagement with said member to prevent its rotation and which is arranged to transmit the thrust of said member to the inwardly-Srojecting post when .the rotation is prevente 18. A transmissioncomprising, in combination, a casing having a hollow boss in its wall, change-speed means arranged' within the casing and including a rotatable member, a stationary post secured in the hollow boss of said casing and projecting inwardly therefrom, and a device lwithin the casing which is movable into engagement with said member` to prevent its rotation and which is arranged-to transmit the thrust of said member to the inwardly-projecting post when the rotation is prevented, said boss being arranged to have an operating lever pivoted thereon on the outside of the casing.

19. A transmission comprising, 1n combination, a casing, change-speed gears within the casing, a safety device movable to engage the teeth of one of the gears to prevent its rotation in one direction, and vmeans ex- ,L tending outsideI the casing for manuallyv withdrawing said device from the gear.`

20. A transmission comprising, in combination, a casing, change-speed gears within the casing, a safety device movable automatically into and out of engagement vwith the teeth of one of the gears when it turns in opposite directions to prevent its rotation in one direction, and means extending outside the casing for manually withdrawing said device from the gear. l

21. A 'transmission com rising, in combination, a pair of interines ing gears, and a h.safety device automatically moved by rotation of the gears in opposite directions to and i from a position between the teeth of said ars. 22. A transmission com rising, in combination, a pair of intermes ing gears, and a relatively large roller automatically moved by rotation of thev gears in op osite directions to and from a position tween the teeth of said gears.

23. A transmission com rising,in combination, a pair of intermes ing gears, and a safety device automatically moved by rotation of the gearsl in opposite directions to and from aposition between the teeth of said gears, said safety device being in the form of a spring dragging against one of the gears and moved by the dragging to and from said position.

24. A transmission comprising, in combination, a pair of intermeshing gears, and a safety device'automatically moved by rotation of the gears in opposite directions to and from a position between the teeth of said ears, saidsafetydevice including a yielding Apart dragging against one of the gears and to move the deviceA by means of the dragging to and from said position.

25. A transmission comprising, in combination, a casing, change-speed means ,ar' ranged within the casing and including a rotatable member. a plunger slidably mounted in the wall of the casing for endkwise movement to and from a position in which it preventsrotation of said member, and means operated by rotation of said member in opposite directions for shifting said plunger tation of said member in opposite directions automatically to and from said position. for shifting said device automatically to and 26. A transmission comprising, in combi- 'from said position. 107V nation, change-speed means including a ro- In testimony whereof, I have hereunto 5 tatable member. a device movable to and signed my nume.

from :i position in which it prevents rotation of said member, and means operated by io- KFNNETH E. LYMAN. 

